contestada

A car is driven for 60 miles. The first 10 miles are through a large city at a speed of 40 mph; once out of the city a speed of V mph is maintained. (a) Calculate the average speed for the 60-mile trip. (b) If you want to average 60 mph for the trip, how fast need you go during the last 50 miles?

Respuesta :

Given: -

Total distance covered d = 60 miles

Speed for first 10 miles V1 = 40mph

Speed for next 50 miles = V

a. Average Speed = Total distance / Total Time

For 10 miles time t1 = 10/40 = 0.25 hrs

For 50 miles time t2 = 50/V hrs

Average Speed Vo= 60 / t1 + t2 = 60 / {0.25 + (50/V)}

Average Speed Vo= 60 V / (0.25V + 50)

b. For Vo= 60 mph

60 = 60 V / (0.25V + 50)

0.25V + 50 = V

V = 50/0.75

V = 66.67 mph

So, he should go with the speed of 66.67mph during last 50 miles.

To learn more about Speed, Time & Distance:

https://brainly.com/question/29949391

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